In the last years, telecommunication systems, in particular mobile telecommunication systems such as GSM (Global System for Mobile communication) and the like, became widely spread all over the world. Due to an increasing competition between network operators the offering of additional services besides the initial object of transmitting speech becomes more and more important.
Recently, a more flexible telecommunication network architecture has been developed, namely the intelligent network (IN). One example of such an intelligent network is CAMEL (Customized Applications for Mobile network Enhanced Logic) which is accommodated to the GSM system. The aim of such intelligent networks is for example to enable the creation of customized services that could be used by subscribers as well as by network operators. Furthermore, the introduction of new services in telecommunication networks shall be facilitated. The central authority in such an intelligent network is a so-called service control point (SCP) which controls distinct calls.
In mobile telecommunication systems, it is essential to know where a subscriber, i.e. a terminal equipment such as a mobile station MS, is located. That is, the location of the subscriber within the network, at least in which area or cell of the network, has to be detectable. There are several methods, as commonly known by persons skilled in the art, by which the location of the subscriber can be determined.
As one possibility, the location can be detected, for example, by accessing a Mobile Location Centre (MLC) for obtaining the latest position of the terminal. For external users, so-called Gateway Mobile Location Centres (GMLC) are provided, which can be directly connected to an external user. These Location Centres (MLC, GLMC) determine the Mobile services Switching Centres (MSC) or Visited Mobile services Switching Centres (VMSC) currently connected to the subscriber in question on the basis of a Home Location Register (HLR) inquiry. By this measure, the latest position can easily be obtained by referring to network elements already implemented in the network.
While it is commonly known that the location information is used for call routing services and the like, also other implementations for the location information are intended.
One example is to use the location information for forwarding specified information to the subscriber, depending on his/her position within the telecommunication network. That is, external users and/or the network operator send e.g. advertisements, tourist information or the like concerning the area in which the subscriber is located.
Therefore, it is necessary, that the sending side knows in which area the subscriber is located, or which subscribers are within a specified area. To obtain this location information, it is to be requested from the telecommunication network. A corresponding request is directed for example to the GMLC by the requesting external user or network operator, and, if the requesting side has access rights for the location information, the GMLC returns the respective location information of the subscriber in question.
However, there is a certain drawback in the above described location requesting method. Hitherto, the GMLC only contains access control records. The subscriber (or user), to whom the specified information is to be forwarded and whose location information is requested, is not directly involved in the decision process whether the request shall be fulfilled or not. Therefore, it is not possible for the user to control to which requesting part the location information is released, i.e. which information (advertisement and the like) he/she receives.
U.S. Pat. No. 5,950,137 discloses a method to provide location information of a target MS to a requesting MS. For this purpose, a secret number is checked in order to decide whether the information is to be released or not.
Document WO 99 55115 discloses the provision of location override keys which can be used to disable privacy settings. Those privacy settings are set by a subscriber beforehand in order to prevent a location application from positioning the MS/subscriber.
U.S. Pat. No. 5,852,775 discloses a method to use advertisements to make calls less expensive. When a registered MS/subscriber establishes a call he is asked, whether advertisements are accepted.